Illuminable Pushbutton Switch

Abstract

Illuminable pushbutton switch in which the button is guided and retained within a tubular shell by fingers extending from a ring interposed between the shell and a base, the fingers having tips extending transversely through openings in the shell and the button. The contact elements of the switch comprise a simple resilient plate within the button adapted to abut the ends of elongated fixed contacts which also serve as switch terminals.

Description

This invention relates to illuminable pushbutton switches and is more particularly concerned with the type of switch which incorporates a lamp that is shunted when the button is pressed.

BACKGROUND OF THE INVENTION

It has heretofore been proposed to provide an illuminable pushbutton switch with a cylindrical shell capable of being mounted simply in a round hole of a panel in the same manner as nonilluminable pushbutton switches, as by spring fingers external to the shell which retain the switch in the hole frictionally. Such an illuminable switch is shown, for example, in U.S. Pat. No. 2,980,784, granted Apr. 18, 1961 to Gohs et al. The virtue of mounting simplicity and appropriate sizing is, however, off-set by an undue complexity of internal switch construction, and particularly by the necessity for manufacturing and assembly a substantially large number of intricately shaped parts. Moreover, in order to replace the lamp, it is necessary to disassemble such switch from the rear.

BRIEF DESCRIPTION OF THE INVENTION

It is accordingly a principal object of the present invention to provide an improved illuminable pushbutton switch or the like of a minimal number of easily made parts which may be assembled very simply to thereby furnish a suitable product at a low-cost of manufacture.

Another object of the invention is to provide a pushbutton switch constructed to permit access to the lamp from the front of the switch so that the switch may be readily relamped.

Briefly stated, a typical switch constructed in accordance with the present invention comprises an insulating base supporting a pair of generally parallel elongated, fixed contact members which project from the base. A tubular shell surrounds the projecting contact members, and a cup-shaped pushbutton slidably received within the shell supports a resilient contact plate adapted to abut the ends of the elongated fixed contact members when the button is pressed. The button is urged outwardly of the shell by a coil spring within the shell and is retained and guided by a retainer ring interposed between the shell and the base. The retainer ring has a pair of retainer fingers extending along the exterior of the shell, the free ends of which are bent transversely or inwardly to extend through aligned holes in the shell and in the button. A lamp is supported between and electrically connected to the fixed contact members. To obtain access to the lamp, it is merely necessary to spring the retainer fingers out of the associated holes and to remove the button.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention will be further described in conjunction with the accompanying drawings, which illustrate a preferred and exemplary embodiment, and wherein:

FIG. 1 is a longitudinal sectional view of an illuminable pushbutton switch in accordance with the invention, the switch contacts being shown open;

FIG. 2 is a similar sectional view displaced by 90.degree. from the view of FIG. 1, this view showing the switch mounted in a panel;

FIG. 3 is a transverse sectional view taken along line 3--3 of FIG. 1;

FIG. 4 is a longitudinal sectional view similar to FIG. 1, but with the contacts shown closed; and

FIG. 5 is an exploded perspective view illustrating the components of the switch.

DETAILED DESCRIPTION OF THE INVENTION

Referring to FIG. 5, the components of a switch in accordance with the invention comprise a base A, a pair of elongated fixed contact members B, a button retainer ring C, an open ended tubular shell D, a washer E (optional), a helical compression spring F, a moving contact plate G, and a button H.

The base A is preferably an electrically insulating disc of plastic material provided with a central well 10 to receive a lamp L, and provided with a pair of spaced, diametrically opposed rectangular bores 12. The elongated, fixed contact members B are preferably flat bars of suitable conducting material provided with tapped holes 14 at one end thereof, and have intermediate projections 16 which seat within laterally enlarged entrances of the bores 12 when the contact members are inserted to extend through the bores, as shown in FIGS. 1 and 4. The tapped holes 14 receive screws 18 to provide terminals for the switch to which lead wires (not shown) may be connected. The lamp L is connected to the contact members B by lead wires 20. The projections 16 limit longitudinal movement of the contact members B with respect to the base A in one direction, and the screws 18 limit their movement in the opposite direction. The base 10 is provided with a second set of opposed bores 13 to enable the connection of the shell D and the retainer ring C to the base.

When the switch is assembled, the contact members B, which project from one side of the base A in substantial parallelism, are surrounded by the tubular shell D. The shell preferably is made of metal. The retainer ring C, preferably of a resilient metal, is interposed between the shell D and the base A. The shell has opposite integral tabs 22 which are received within notches 24 of the retainer ring to orient the ring. As shown in FIG. 2, the tabs are passed through the bores 13 of the base, and the tabs' free ends are bent over upon the back face of the base to secure the shell and the retainer ring to the base.

The button H is preferably cup-shaped and is preferably formed or molded of a light-transmitting material (at least part of the closed button end). Examples of light-transmitting materials are the acrylic resins, the cellulose acetates or the like which are transparent or translucent to light. The contact plate G, preferably formed of a resilient conductive material, is supported within the button H adjacent the closed end thereof as shown in FIGS. 1, 2 and 4. The contact plate, which preferably is cruciform in shape as shown in FIG. 5, is provided with teeth 26 angulated as shown in FIGS. 2 and 5 to engage and bite into the tubular sidewall 28 of the button when the plate is forced into the button adjacent the button's closed end wall 30. The contact plate is formed to provide contacts 32 which overlie adjacent ends of the elongated, fixed contact members B when the button is slidably received within the shell D as shown in FIG. 1. The contacts 32, which are movable with the button, preferably are spaced slightly from the closed end 30 of the button to permit resilient engagement with the fixed contact members. The coil spring F is positioned within the shell D, as shown in FIGS. 1, 2 and 4, one end of the spring engaging the lower edge of the button's wall 28, and urging the button outwardly of the shell D. To assure engagement of the spring with the button, the open end thereof may be formed with an internal annular flange 34. The other end of the spring engages the insulating washer E adjacent to the base A. If desired, the washer may be omitted, whereby the spring engages the retainer ring C or the end internal rim 36 of the shell D.

The retainer ring C is provided with a pair of diametrically opposed retainer fingers 38 which extend along the exterior of the shell D. The free ends or tips 40 of the fingers are bent transversely or inwardly, and extend through aligned openings 42 and 44 extending through the shell and button, respectively. The openings 44 have sufficient width and length to permit the button to move longitudinally relative to the retainer fingers' tips 40, so that the moving contacts 32 may engage the elongated, fixed contact members B, as shown in FIG. 4, and may be disengaged from these members as shown in FIG. 1. The coaction of openings 44 with the tips 40 of retainer fingers 38 thus serves to limit the outward movement of the button under the pressure of spring F and to guide the reciprocative movement of the button for proper switch closing. The contact plate G must of course be properly oriented within the button. The retainer ring C also is provided with the usual friction fingers 46 for holding the switch within a circular opening 48 of a panel 50 as shown in FIG. 2. The friction fingers are bent as shown to furnish the spring effect. The shell D is provided with an annular flange 52 which abuts the panel 50 in the usual manner.

A conventional incandescent lamp L is supported between the elongated, fixed contact members B, the base of the lamp extending into the well 10, and the lamp leads are connected to the contact members. The contact plate G is provided with an aperture 54 to increase the light from the lamp which is transmitted through the button H. When the button is pressed, the lamp is shunted and extinguished, and a circuit is completed between the switch terminals at the screws 18.

It is apparent from the foregoing description that the pushbutton switch of the present invention comprises a minimal number of parts, which, by virtue of their simple configuration, are economical to manufacture and easy to assemble. The retainer fingers 38 of the button retainer ring C are formed from the material between the friction fingers 46, and would ordinarily be scrap and discarded. The switch is readily disassembled from the front to expose the lamp by merely springing the retainer fingers 38 out of the associated openings 42 and 44 to release the button, which may then be removed.

Although in the illustrated form of the invention the lamp terminals are shown connected to the fixed contact members B by conductors 20 which are soldered in holes of the fixed contact members, it will be appreciated that if the lamp is connected to the fixed contact members by clips, such as tubular clips slipped over the ends of the fixed contact members, the replacement of the lamp is greatly facilitated. The button is easily reassembled with the remainder of the switch by springing the tips of retainer fingers 38 back into the button openings 44. Not only is the switch of the invention simpler to manufacture, assemble and disassemble than comparable switches known heretofore, but the contact elements are simpler in their construction and mode of operation, merely requiring a simple shunting plate G for abuttingly engaging the ends of the elongated, fixed contact members B, thereby avoiding the need for slender, especially formed, longitudinally extending moving switch contacts. The contact members also serve as switch terminals at their opposite ends.

While a preferred embodiment of the invention has been shown and described, it will be apparent to those skilled in the art that changes can be made in this embodiment without departing from the principles and spirit of the invention, the scope of which is defined in the appended claims.

Claims

We claim:

1. An illuminable pushbutton switch or the like comprising an insulating base having a pair of spaced, elongated contact members projecting from one side of the base, a tubular shell extending from said side of said base and surrounding the projecting contact members, a button slidably received in said shell at the end opposite to said base, spring means within said shell urging the button outwardly of said shell, contact means supported by the button adapted to engage the contact members when the button is pressed inwardly of the shell, and a button-retainer ring interposed between the base and the shell and having a pair of spaced fingers extending along the exterior of said shell, the shell and button having respective pairs of aligned openings, and the fingers having inturned ends extending through the shell openings and into the button openings, the button openings having sufficient length to accommodate the movement of the button when it is pressed inwardly of the shell, the fingers' inturned ends limiting the movement of the button outwardly of the shell.

2. An illuminable pushbutton switch or the like in accordance with claim 1, wherein the fingers of the retainer ring are resilient, whereby the fingers may be sprung out of the button openings to release the button.

3. An illuminable pushbutton switch or the like in accordance with claim 2, wherein the retainer ring includes resilient friction fingers extending along the exterior of the shell for holding the switch within a mounting hole.

4. An illuminable pushbutton switch or the like in accordance with claim 1, wherein the button is substantially cup-shaped and the contact means comprises a plate within the button adjacent to the closed end thereof, the plate having teeth engaging the sidewall of the button for supporting the plate and having resilient contacts adapted to abut the ends of the contact members.

5. An illuminable pushbutton switch or the like in accordance with claim 4, wherein the plate has an opening therethrough and the closed end of the button is of light-transmitting material.

6. An illuminable pushbutton switch or the like in accordance with claim 5, wherein a lamp is supported between the contact members and has terminals electrically connected thereto.

7. An illuminable pushbutton switch or the like in accordance with claim 1, wherein the shell is affixed to the base by tabs extending from the shell through the base.

8. An illuminable pushbutton switch or the like in accordance with claim 7, wherein the retainer ring has notches through which the tabs are extended to orient the ring relative to the shell.

9. An illuminable pushbutton switch or the like in accordance with claim 1, wherein the contact members extend through bores in the base and have ends projecting from the opposite side thereof.

10. An illuminable pushbutton switch or the like in accordance with claim 9, wherein the contact member ends have screws threaded therethrough, respectively, adjacent to said opposite side of said base.

11. An illuminable pushbutton switch or the like in accordance with claim 10, wherein the contact members have flanges seated within enlargements of the bores at said one side of said base.

12. An illuminable pushbutton switch or the like in accordance with claim 1, wherein the spring means comprises a coil spring surrounding and spaced from the contact members.

13. An illuminable pushbutton switch or the like in accordance with claim 6, wherein the retainer ring includes resilient friction fingers extending along the exterior of the shell for holding the switch within a mounting hole; wherein the shell is affixed to the base by tabs extending from the shell through the base; wherein the retainer ring has notches through which the tabs are extended to orient the ring relative to the shell; wherein the contact members extend through bores in the base and have ends projecting from the opposite side thereof; and wherein the contact member ends have screws threaded therethrough, respectively, adjacent to said opposite side of said base.